Search results
Results from the WOW.Com Content Network
In general opaque glass can devit easily as crystals are present in the glass to give its opaque appearance and thus the higher the chance it might devit. Techniques for avoiding devitrification include cleaning the glass surfaces of dust or unwanted residue, and allowing rapid cooling once the piece reaches the desired temperature, until the ...
Optical glass refers to a quality of glass suitable for the manufacture of optical systems such as optical lenses, prisms or mirrors.Unlike window glass or crystal, whose formula is adapted to the desired aesthetic effect, optical glass contains additives designed to modify certain optical or mechanical properties of the glass: refractive index, dispersion, transmittance, thermal expansion and ...
Obsidian is mineral-like, but not a true mineral because, as a glass, it is not crystalline; in addition, its composition is too variable to be classified as a mineral. It is sometimes classified as a mineraloid. [20] Though obsidian is usually dark in color, similar to mafic rocks such as basalt, the
Murano glass makers developed the exceptionally clear colourless glass cristallo, so called for its resemblance to natural crystal, which was extensively used for windows, mirrors, ships' lanterns, and lenses. [21] In the 13th, 14th, and 15th centuries, enamelling and gilding on glass vessels were perfected in Egypt and Syria. [44]
Dizzy cocktail glass, a glass with a wide, shallow bowl, comparable to a normal cocktail glass but without the stem; Faceted glass or granyonyi stakan; Highball glass, for mixed drinks [6] Iced tea glass; Juice glass, for fruit juices and vegetable juices; Old fashioned glass, traditionally, for a simple cocktail or liquor "on the rocks" or ...
The window depicts two biblical passages in which women, also painted with dark skin, appear as equals to Christ. WARREN, R.I. (AP) — A nearly 150-year-old stained-glass church window in Rhode ...
If you're wearing makeup (see below for the best makeup for glass skin), you may want to try a double-cleanse. Exfoliate. Glass skin is all about radiance and glow—and the best way to lay the ...
Materials that allow the transmission of light waves through them are called optically transparent. Chemically pure (undoped) window glass and clean river or spring water are prime examples of this. Materials that do not allow the transmission of any light wave frequencies are called opaque. Such substances may have a chemical composition which ...